Objectives: Prostate cancer’s prevalence is rapidly increasing in Korea, with incidence rates rising by over 13% annually since 2017 according to the Korea Central Cancer Registry, highlighting the need for effective early detection strategies. This study systematically reviews the benefits and harms of PSA-based prostate cancer screening, focusing on its clinical effectiveness and public health implications. Methods: Following PRISMA 2020 guidelines, we searched five databases (PubMed, Embase, Cochrane Library, Google Scholar, and KMbase) for studies from 2014 to 2024. The eligible studies included RCTs, cohort studies, meta-analyses, and guidelines. Risk of bias was assessed using the Cochrane tool. We synthesized our findings narratively due to their methodological heterogeneity. Results: Sixteen studies were included. PSA screening reduced prostate-cancer-specific mortality by 20–31%, as reported in multiple randomized controlled trials, such as ERSPC and ProScreen, among men aged 55–69, but showed minimal impact on all-cause mortality. Advanced tools such as MRI and multi-biomarker models, which were implemented in several included studies, enhanced diagnostic accuracy. The potential harms included overdiagnosis, overtreatment, and psychological distress. Community-based education and shared decision-making, inferred from observational and implementation studies, improved participation and equity in screening. Conclusions: PSA-based screening offers modest mortality benefits but carries the risk of overdiagnosis. Precision diagnostics and risk-stratified strategies improve screening outcomes. Public health approaches, particularly those led by nurses and community health workers, are essential to promoting informed, equitable screening decisions.